Printing cut and method of making it



June 27, 1944. J, T. cocHRAN PRINTING CUT AND METHOD OF MAKING IT Filedsept. 3o, 1940 2 sheets-sheet 1 INV ENT OR BY 40AM d@ June 27, 1944.

J. T. COCHRAN PRINTING CUT AND METHOD OF MAKING IT 2 Sheets-Sheet 2Filed sept. 3Q., 1940 Patented June 27, 1944 PRINTING CUT AND METHOD orI MAKING IT Joseph T. Cochran, Chicago, Ill. A' Y Application September30, 1940, Serial No. 359,032 t (c1. i-395') YThis invention relates ingeneralto a printing I 9 Claims.

cut having a sectional flexible conforming backing which preventswarping and is type high requiring no make ready.

-An important object of the invention is inthe provision of a sectionalblock backing'in which the grain of the block, lif made of Wood, isperpendicular to the line vof printing pressure so that the backing isrelatively non-compressible. A further object of the invention is in theprovision of 'a backing, comprising a plurality of intereng'agedconnections which together form a somewhat exible mat, variable in size,but relatively y'incompressible and rigid when attached to a-printingplate. 'I

still'further object of the invention'is to connectia printing plate orfilm to a somewhat flexible blockingmaterial by means of a thermoplasticmaterial which takes up4 the inequalities ofthe back of the plate andalso transforms the flexible backing blocks into a relatively solidnonwarping back which is 'of the proper height for correct printing whensubjected to pressure which eliminates make ready.V

f vAstill'further object ofthe invention isin the methodof'making aprinting cut by uniting a printing plate or -lm to a flexiblesectionalblock baseby means'of a thermo-plastic material under heat andpressure which unites the sections into a solid flexible base andpermanently connects-the printing plate thereto ready for use.

Other objects of the invention will` appear in the specification andwill be apparent from the accompanying drawings in which l ,Figli isa`perspective of a sectional block base inaccordance with the invention;

E i'g2 is a sectional view of a number of block units, to which aplastic or adhesive coating has Vbeen'applied;

, Figs is .a view'simnartfrigjz@ settling th printing cut'in which thegrain of 'the units is at right angles to the printing thrust to preventundue compression, the edges lof' the units or sections heinginterengaged for uniting them into a common mat which is more-or-lessflexible and conforming for application to the back of a 'thin printingVplate which is united thereto by means of a thermo-plastic layerplacedunder heat and pressure to produce a compact unitary printing cutvpressed under barriers exactly type high, thus l making itincompressible and non-warping and therefore requiring little or no makeready due to the conforming block units.

Referring now` more particularly to the drawings, a plurality of blocksI0 are shown more clearly in Fig. 1,' each of regular size, a littleless than type high, and'having the grain, if made of wood, 'runningfrom top to bottom, that is, per` pendicular' to the vpriming surface'sothat there will be lthe greatest Iopposition' to any'compression of the'block in the lprinting direction. Each rangement.

application of a thermo-plastic coating ,or layer:v r f 4 is a similarView showing the addition of an adhesive layer; Y

` 5 is asimilar view illustrating the `addition of a printing, plateanda lthermo`plas'tic fand adhesive-layer at the bottom of theV blocksection; fFig. 6 is va somewhat diagrammatic view showingtheapplicationof heat and 'I 'nr'ess'ure'v to the asseriiblyshownV in Fig.5 for producing a complete printing cut; and iFig.' rl-is an enlargedsectionalviewillustrating thefpen'etration "of inequalities'at' Vthebacktof a printin'gplate into the thermo-plas'tic'coating due to theAapplicationI of heat 'and pressure? i"In thefrnaking of printingcutsitis' customary toprovide a printing plate'oflheavy metal with afwood orother backingwhich is made'exactly type high. Large cuts,Ainzparticular, become im As commonly produced, v'theY blocks lit orslide easilyv together forming@ somewhat iiexible mat o'finlegrxiblesections, ythedifferent blocks or units slidin freely `with respect topeach'otherso'that theyQchnform easilyvv to a common surface 4orplaneupon which they ,are placed.

,A number-.ofthe ,blocksjorfunits I0 areas'- sembled in thismanner,fforming a exible jointed i matof the desired size' .andaprinting yplatey I5 is applied to the upper surface `by means of. in-

terposed layerv I 6 of thermal-plastic v material usu-` ally in, 't theA,ferm of a` thin'- plastic .impregnated paper or felt sheet. vA layeror coatingofy adv'-V hesive l1 may first be-applied'to .the topof theblocks, the. layer I5 applied thereto, and anotherV layervof adhesive Ilv.placed on top .of the layer I6 to'which the under surfaceof theprinting; n plate I5 `is tljlenappliedv;` Beforefsubjecting the y lassemblyofthe plate vand backing lt'o heat 4and pressure, an adhesivevcoatrl8 v.may be appliedta thermo-plastic layerV I 9,; similar Y tothelayer 'I l is gpp'liedfat :the-bottom-:ofthecut assenfihly, As vthusassembled theput is lplacedin a press havingra -relativelyfi'lxed base2l)` and afmoyable' top 2| whichgisrepresented as hollow and heated by aflo'waof steam or the--likefthrough an inlet pipe 22 andk anf outletpipe23 with suitable gauges;

24 to limit the compressi'on'o'f thegcut assembly while subjected toheat and pressure to a print- ,ing cut which is exactly type high.

Any inaccuracies of the backing blocks, the plate or any ofthe otherlparts is thus taken up by the thermo-plastic layer and the sectionalblocks are sealed tightly together to provide a non-warping andpractically incompressible plate backing which is coated both on top andat the bottom by an impervious layer which prevents warping anddistortion of the block even though subjected to rough usage.

In an actual mounting of a printing plate as represented in enlargeddetail in Fig. '7,the plate is represented as having a printing surfacewhich may consist of highlight and shadow portions 25 and 26 withvarious points and projections 21 at the under side or back thereof. Aspressure is applied, these points or projections are caused to penetratethrough the upper layer l1 of adhesive and into the thermo-plastic layerI6 in which they become embedded, thus taking up any roughness or anyqualities on the underside of the plate, leaving the printing surfacethereof smooth and with the printing surfaces all in a common plane. Thecontact of the underside of the plate with the thermo-plastic layer maybe distorted in various ways other than as represented in Fig. 7, theessential feature of which is thatthe layer is of su'icient thickness totake up the points or projections of the underside ofthe plate and tomake a rm and lasting; contact therewith, embedding the projections anduniting the plate to the upper side of the sectional block mat. Theunderside of the block sections are similarly united and any unevennessis smoothed or leveled by the applicatio'n of the thermo-plastic bottomlayer thereto. v Y

When a cut has been made in this manner, the edges of the block backingwhich project beyond the edges of the printing plate applied thereto,may be trimmed therefrom in any suitable mane ner, the outer line 28 ofthe backing as shown in Fig. l representing the trimmed edge thereoffrom the full section of the connected block units,. the outeredges ofwhich` are represented by the broken outline 29.

With this constructiomthe backing may beV fitted to the plate r4eitherbefore the plate is fastened .thereto for the backing may be trimmedafter the plate is attached by the method above described. In `eitherway, la backing of the proper or `vapproximate size is quickly suppliedfor and easily applied to a plate of any size, andY after the printingplate is applied, it adheres tightly 'to the backing' without requiringany fastening'V nails which ,frequently distortr'the edgesf the printingeut making it-upm for use.

"I claim:` Y

The A ceri-ibination with a printing -'plate ,memberl of a backingtherefor comprising a plurality of blockse'ctions vhaving interengagingportions and inter-connected loosely together to' Y fr'm ai somewhatflexible' but relatively 'incompressible mat, and meansforsealing thememberfto the'topsof the vsec'stionsY 'and uniting them into acomparatively rigid non-warping 'basel 2. VTh'e f'zo'nribin'at-ionvwith'la prmting "plate, of aba'cking therefor 'comprising a plurality.`ofv separate'blo'cks, the blocks having interenga'ging portions by whichthey are loosely 4assembled inV 'flekibl'ematwhich' may be varied insize andr Simp@ randa- Itherme plastic layer uniting the bacllof theplate and the blocks at their tops to form a'relatively rigid'fprinting`cut..

3. The combination with a thin printing plate, of a sectional backingtherefor comprising a plurality of block units, `interengaging portionsat 'the edges of the blocks for assembling them in a loose flexiiblemat, a thermo-plastic layer between the plate and backing, adhesivemeans securing the plate, layer and backing torgether, and anothercovering layer attached to the rear of the backing and firmly connectingthe sections thereof.

4. In a printing cut, a thin printing plate with uneven projections atthe under side, a sectional block backing, interengaging means at theedges of the blocks for loosely and flexibly assembling them, and aconnecting pressure adhesive layer between the plate and block with theplate projections imbedded in said layer leaving the printing face in acommon plane.

5. In a printing cut, a printing plate with printing projections in acommon plane on the outer face and uneven projections on the under face,a flexible loosely interengaging and connected sectional block backing,an adhesive thermo-plastic layer connecting the plate and backing, thesaid uneven projections imbedded in the layers to unite the blocks andplate into a solid rigid cut.

6. The method of making printing cuts'with a printing plate, whichcomprises assembling a plurality of base blocks of a combined area asgreat or greater than the area of the plate, interengaging the edges ofthe blocks to form a flexible mat of the size and shape desired, andapplying an adhesive layer between the back of the plate and the surfaceof the blocks to bind them together and provide a rigid backing for Vtheplate.

'7. The method of making printing cuts with a thin printing plate havinguneven projections on the back, comprising the assembling of a flexiblemat of loosely interengaged backing block units to cover the back of theplate, in interposing a plastic hardening layer between the faces of theblock units and the back of the plate, and in applying pressure to-embed the projections in the layer and to secure the block unitsthereto in a common rigid base.

8. The method of making printing cuts with i a thin printing platehaving uneven back pro.

jections, which comprises assembling av flexible back mat of looselyinterengaged separate blocks. as large or larger than the plate, in,interposing a layerofthermo-plastic material between theY hack of theplate and the tops of the blocks, and inl subjecting this assembly toheat` andV pressure to embed the projections in the layer and. torigidlyconnect the blocks in a common baseof l proper-height therefor. YY

9,'The method of makinggprintingcuts with a thinzprinting plate whichhas uneven Aback projections, which comprises Vvassembling and; looselyvinterengaging a plurality of backing block units suicient to cover the-back'of the;

the-units into a solid base, and in applying'a bottomv cover tothe-backing units topseal the spaces between the units. v

- ,g-.Q JosEPH '1'. 'coCHRAN.-- w

